Oral IgY against human rotavirus administered within 24 h after virus challenge to suckling mice was still effective and decreased the incidence of diarrhea . Egg yolk and colostrum powders containing specific antibodies against bovine coronavirus (BCV) antigen was evaluated in a challenge model with a standardized dose of virulent BCV strain. Daily treatment with these antibody preparations started 6 h until 7 days post-challenge. Control calves which received no antibody had severe diarrhea and all died within 6 days after infection. In contrast, calves fed milk containing egg yolk or colostrum with high antibody titers all survived and had positive weight gain. The study showed that specific antibody preparations protected against BCV-induced diarrhea in neonatal calves and that the egg yolk used provided a higher degree of protection compared to colostrum powder on a titer basis.

A field trial with oral administration of chicken IgY specific for bovine rotavirus (BRV) resulted in a significantly increased mean body weight (P < 0.05) and a decrease in number of calves shedding high titer of BRV in stool compared to control calves (P < 0.01). Passive oral immunization with yolk immunoglobulins has also been shown to protect mice against experimental bovine rotavirus-induced diarrhea.

Humans

There are differences in using avian or bovine immunoglobulins. In a

randomized, placebo controlled clinical trial, children with rotavirus diarrhea was treated with IgY from hens immunized with Wa, RV5, RV3 and ST3 rotavirus strains. There was a significant reduction in stool output (g/kg/day) and viral clearance in the group treated with specific IgY compared to placebo. However, there was no difference in diarrhea duration. Oral treatment with bovine anti-rotavirus colostrum resulted in a reduction of rotavirus-associated diarrhea in infants. It also reduced the infection rate in children.